Improvement in lamp-chimneys



M. w, HOUSE. 'Laimp Chimney.

Patented Mar. 7

- N-PETERS, FHOTO-LITHDGRAPHER, WASHINGTON. D. C.

tater IMPROV ME T in w Tccll'wltcm it manconcern:

'Be it known that I, Mkn nwxeerns Honsn, of jgleveland, in the county of-Guyahoga and State of i hio, ful Improvementsin Lamp-0himneys; and that the I following is a full, clear, and exact description and 1 specification of the s'a me.

The Objects of my improvements are to iinprovethe light of circular-wick lamps, and tosecurethe chimney i to the lamp. To this end f The firstpart of my invention consists in constructingthe portion of thelamp-chimuey immediately above the choke or throat substantially in the form of a par 1 abolic' spindle, whose apex isat or in the vicinity of, the level of the upper edge of the wick when homing. This form tends to prevent the formation of eddy cur- I rents in the portion of the chimney immediatel bove the throat, and, in connection with the enlargement of the cylindrical shaft oi'the chimney, greatly increases the light obtained from thelamp ascompared with the light obtained withchokechimneys of the usual construction. r A H My next improvement. consistsinthe constrnction slip-choked lamp-chimney rounded .1; of the lower end of a inan inward direction, so that, when such a choked I chimney is applied to slipchimney fastenings, it readily enters betweeenthem, and the risk of catching a point of a fasteningwithin the rim of thechimney is avoided. My next improvement consists in the construction of a slip-lamp chimney with a supplementary shoulder below the shoulder of the choke which deflects the air npontheflame, the objectof the said supplementary shoulder being to provide an abutment with which the pointsof slip-chimney fasteningscan engage, so as to hold the chimney more securely} to the lamp,

In order that m y. invention may be fully understood, I have represented in the accompanying drawing two sectional views of chimneysoflthenatural size,

Eigure 1 representing my improved chimney in connecltion with some parts of a lamp to which it is fitted; ant r i i 1 Figure2 representing a chimney of the old coustrnction. i S

Choke-chimneys of the old construction are choked abruptly, as secn at B, fig. 2, soas to form a throat, A"; and this choked portion A'f is connected with the straight chimuey-shaft 0', above, bya short circular. curve, 0, so as to prodncean abrupt enlargement of the sectional area otthe chimney, As there is a strong current of heated air passing through the throat, and 1 as currents offiuid tend to issue {from such a throat in the form of what is known in hydraulics as the vena nontracta, the effect of the sudden enlargement of the 1 chimney above the threat is, as I believe, to afihrd have made an invention of certain new and use i Letters Patcntlio. 112,460,1iatcdMarel17,1871; antedated lharch1, 1871.

LAMP-CHIMNEVS.

The Schedule referred to in these Letters I Patent and making part or the same.

space forthe formation of counter eddies, which diminish the intensity of the draught and aii'ectthe quantity of the light producedby the lamp.

7 To obyiate this defect, I construct the portion 0, fig. 2, of the chimney between the throat or choke A and the straight shaft 0, above, in the form of a parabolic or elliptic spindle, whose apex as shown by the dotted lines j, is at or about the level of the wick when burning. By this mode of construction the sectional area of the chimney. above the throat may be made to increase snbstantially as required to produce the best draught, and the enlargemcntvanishes into the straight shaft 0, above, with an easy curve, so that no space is afforded above the throat for the formation of eddiesat the sides of the main current throat. t

The-construction of the portion of the chimneyabove the throat in the above-described manner permits the straight shaft 0 to be made of larger diameter with advantage; and the practical'results are, a greater passing through the draught, an increased and more perfect combustion of the burning fluid, and a great increase in the volume of light obtained from the wick, as compared with that obtained from the same wickwith a chimney of the old construction, such as is represented at fig. '2.

' Slip-chimneys previous to my invention have been constructed with their bases D, fig. 2, cylindrical down to their lower ends. Hence,'inasmi1ch as the slip chimney fasteuings are constructed to converge with a yielding pressure for thepnrposeof grasping the chimney, and converge, to a circle smaller in diameter than the exteriorof the chimney-base when it is withdrawufrom them, the application of such a chimney to the fastenings g'enerallyresults (unless care is exercised) in engaging one or more chiiimey-iastenings inside of the base of the chimney, thereby requiring the withdrawal and replacement of the chimney, and sometimes resulting in the bending of the chimneyfastenings.

To obviate these defects, I construct the base D, fig. 1, of a slip-chimney with its lower end or rim s rounded inward, so that the lower end of the chimncymay be contracted to a circle of smaller diameterthan the circle to which the points of the chimney-fasteuings tend to converge. Hence the base of the chimney can always be readily entered between the points of the chimneyconstructed with cylindrical bases, as at D, tig. 2, so

that the chimneyastenings hold the chimney by lateral pressure only; for, although such lamp-chimneys are generally constructed with a shoulder, as at t, fig.

ffilit'.

MARK wIeeINs house, or oLnvnLaungonio, ASSIGNOR ro 'rnn oLnvE- LANDNON EXPLOSiVELAMP COMPANY, or SAME PLACE.

2, the fastenings cannot be extended upward to engage with such a shoulder, because they would then intercept the passage of light laterally from the wick.

The holding of the chimney by lateral pressure alone 's precarious, and, therefore, 1 construct the base of the slip-chimney with a supplementary shoulder, r, fig. intermediate between the lower end of the chimney and the choke or throat;

This supplementary shoulder furnishes an abutment with which the ends of the spring slip-chimney fastenings got the chimney-holder can engage by overlapping it, so that the chimney is held'not only by the lnteral pressure of the fastenings, but also by their downward pressure; hence, the chimney with the supplementary shoulder is held in its place much more securely than chimneys of the old construction are.

Having thus described my improvements, I declare that I do not limit them to the exact form represented in thedrawing; but.

\Nhat I claim as my invention, and desire to secure by Letters Patent, is

1. The lamp-chimney, constructed above the throat substantially in the form of a portion of n parabolic spindle, as hereiubefore described.

2. The slip-lamp chimney, constructed both with a. choke between its base and shaft, and with the lower end of its base rounded inward, as hel'einbefore'described.

3. The slip-lamp chimney, constructed with a. supplementary shoulder upon its base for engagement with the ,ends of slip-chimney fasteniugs, as hereinbefore set forth.

In testimony whereof I have hereto set my hand this 11th day of July, A. D. 1870.

MARK. W. HOUSE.

Witnesses:

E. S. RENWICK, W. L. Bnmsmr. 

